Teak is a medium to large-sized tree, which shed off its leaves at least once a year. It reaches to about 50 m high with irregularly formed crown and with low buttresses. In natural stand, the trunk is generally straight and branchless up to 20 m with up 250 cm diameter at breast height. Sometimes small branches sprout on the main trunk. The bark is light brown to grey, the dead outer bark greyish black and drop off in short longitudinal flakes. The ultimate young twigs are four-angled in cross section. The leaves are simple oppositely in pairs and alternately at right angles with each pair which form four rows termed decussate and some are in three (ternate). The leaf blade is egg to lance-shaped, sometimes broadly egg-shaped, big, about 36 cm broad and 54 cm long, the base is wedged-shape, the top abruptly pointed, leathery, the surfaces hairy, rather rough to the touch on the above surface. The young leaves are more or less purplish. Cluster of flowers are terminal and sometimes axillary. The flowers are bisexual, i.e. both pistil and stamens are in one flower. The flowers are loosely set in the flower clusters. The fruits are somewhat fleshy when green, more or less rounded, slightly four-angled, when dry woody. The seeds are without albumen (nutritive material stored in seed), i.e., endosperm.

Acrid, cooling, laxative, sedative and possess anthelmintic and expectorant (wood).

Sagon

Tectoquinine (leaf and heartwood); tactole and lepachol (heartwood); betulin (stem bark); betulinic acid (root, stem bark, wood).

In bronchitis (bark decoction), inflamed eye lids (ash from wood) and anuresis (root); to relieve the swelling of eyelids (charred wood); as a hair tonic (wood oil).

Chandel et al., Biodiversity in Medicinal and Aromatic Plants in India.